ASME Residential Propane Tank

ASME is a certification for tanks that are typically larger and used for home heating or additionally heating and appliances. These tanks are designed for stationary installation thus are not designed to be moved when containing propane. The design and standards are governed by American Society of Engineers aka (ASME).

500 Gallon Propane Tank

Pressure inside an LPG tank does not change when the LPG level in the tank changes until the tank is almost completely empty, save from the impacts of temperature variations. The pressure in the tank will only be affected by the ambient temperature if there is enough LPG in the tank to make liquid LPG. Regardless of tank fill level, the pressure will be the same at -20F (seal level), or 11.5 psi. When the last of the liquid is nearly consumed liquid will boil in the tank to a vapor as pressure drops. In summary, a 500 gallon LPG tank at -20 F will have roughly 11.5 PSI.